Know Vivian Liberto primarily though Ginnifer Goodwin’s performance in Walk the Line as the nettlesome obstacle in the way of June Carter and Johnny Cash’s storybook romance? Join the club.

Righting that false depiction is the primary impetus for Matt Riddlehoover’s My Darling Vivian, a purely informational bio-doc on Liberto, aka Cash’s first wife, as told by their four daughters — the last survivors who can most accurately tell her story.

Recollections by Roseanne, Tara, Kathy, and Cindy Cash form the heart of the film and provide engaging — and occasionally conflicting — insights into their mother’s eventful life, which took a tragic backseat to the June & Johnny Show once it became clear to the PR gods that any acknowledgment of his earlier marriage went against this country music fairy-tale narrative.

As a storyteller, gatherer of interviews, and an assembler of archival footage, Riddlehoover is terrific, but as a filmmaker, he’s merely serviceable. In the rare instances when he attempts something creative, they come off as empty flourishes, namely animating cigarette smoke in still photographs. And though Liberto is depicted as camera-shy, having one video clip with audio — and saving it for the very end of the film — feels cheap and shortsighted.

The mere fact that Liberto’s story has finally been told — her 2007 memoir was unsurprisingly also buried in the wake of Walk the Line — is a major victory, but there remains a sense that she deserves far better.

Grade: B-minus. Not rated, but with adult themes and language. Available to rent via Grail Moviehouse

(Photo: The Film Collaborative)